Disposable syringes: syringes that were supposed to be discarded after their use. Unfortunately, those syringes are being re-used, as proven by the statistics. About 25% of AIDS cases are directly attributable to disposable syringes.
There are several brands and models of syringes available in the market. However, no model is really disposable. They are only designed with the objective of guaranteeing the quality and sterility of the product. Therefore, it is of extreme importance that measures be taken so that these syringes can really be discarded, avoiding the burden of additional expenses to the health system due to their re-use. The warnings xe2x80x9cTo be used only oncexe2x80x9d or xe2x80x9cTo be destroyed after use!xe2x80x9d printed in the packing don""t guarantee that the product will be discarded. There are no secure ways of supervising the final user of the product. If each sold unit were really destroyed after its use, the cost with syringes would be ridiculous, when compared with the economy generated by the reduction of the health expenses attributable to the sharing of disposable syringes.
The present invention is about a xe2x80x9cDisposable Syringe with a plunger rupture devicexe2x80x9d or, more accurately, about a device of automatic action which permits the syringe to be used only once. The syringe is characterized by a device that allows the charging of fluids as in any common syringe; however, when the piston has its course reversed, the pressure that the user exercises in the plunger, and, consequently, in the piston, receives a contrary pressure from the fluid. At this point, the device is triggered: the rubber suffers a deformation, expelling the support bolt from the set plunger/piston. This make the claws at the plunger lose their grip and the piston detaches itself from the plunger, getting stuck at the bottom of the barrel, making impossible a second use of the syringe.